First report of Gambierdiscus in the
Western Mediterranean Sea (Balearic
Islands)
Gambierdiscus (Dinophyceae) species
are benthic dinoflagellates living in marine littoral zones of circumtropical areas and have recently been described in
temperate waters [1]. Some species are
producers of potent neurotoxins: ciguatoxins (CTXs) and maitotoxins (MTXs).
Ciguatoxins are linked to Ciguatera Fish
Poisoning (CFP). Ciguatera used to be
restricted to tropical and subtropical
areas, but since the last decade, it appears to be expanding to more temperate latitudes. For example, outbreaks
of ciguatera have been reported in the
Canary Islands and Madeira (eastern
Atlantic Ocean), where several species
of the genus Gambierdiscus have been
identified [2].
In the Mediterranean Sea, no thorough evidence of cases of ciguatera exist. The only reports of CTX-like toxins
in fish, which are not confirmed, were
based on the Cigua-Check Fish Poison
Test kit (Oceanit, Hawaii), a method
that has proved to be unreliable [3].
Nonetheless, Gambierdiscus species
have been reported in the last decade
in Crete and Cyprus (eastern Mediterranen Sea) [4-6]. One species of Fukuyoa (F. paulensis), a genus that includes
species previously included in the genus Gambierdiscus, was reported in
the Balearic Islands in 2015 [7]. Little
is known about diversity, distribution
and toxicity of Gambierdiscus spp. in the
Mediterranean Sea. The present study
confirms the presence of G. australes in
the two Balearic Islands of Majorca and
Minorca, and this constitutes the first
report of Gambierdiscus genus in the
western Mediterranean Sea.
In this study, microalgal samples
were collected from macroalgae and
rocky substrates in 19 stations in Majorca and Minorca in September 2017.
Water temperatures ranged from 24 to
27 C and salinity from 36.2 to 38.0. In
the laboratory, samples were observed
under the microscope and individual
cells were isolated with micropipettes
to establish cultures for morphological and molecular analysis. Calcofluor
white stain was used for morphological
identification. Cells were observed with
a compound microscope equipped with
epifluorescence at 630X (Leica DMLB).
The Gambierdiscus cells observed were
anterior-posteriorly compressed. Morphology of the epitheca and the hypotheca is shown in Fig. 1 in which the plate
terminology employed follows Fraga
and collaborators [8]. The epitheca has
a rectangular-shaped 2 apical plate
and the P0 plate is ventrally oriented;
the hypotheca has a narrow 2 plate
equivalent to 1p plate in Chinain [9].
The cell surface is smooth. The cell
length and width of 62 individuals were
measured. Length ranged from 60.9 to
92.3 μm (mean of 75.6 μm) and width
ranged from 64.1 to 90.8 μm (mean of
78.6 μm). The original description [9]
described a length range of 76-93 μm
and a cell width of 65-84 μm. Further
morphological analysis will be performed using electron microscopy.
To facilitate molecular identification to species level, DNA was extracted
from individual or a few clonal cells
using the ArcturusTM PicoPureTM DNA
Extraction Kit (Applied Biosystems, CA,
USA). Afterwards, the domain D8-D10
of the LSU rRNA gene was amplified by a
Polymerase Chain Reaction (PCR) using
the pair of primers FD8 and RB [9], and
products were sequenced. The D8-D10
sequences obtained in this study were
deposited in GenBank under accession
numbers: MG708117- MG708130. DNA
sequence analysis of amplified rDNA
fragments confirmed that all Gambierdiscus spp. corresponded to G. australes,
which was in accordance with the morphological identification. G. australes
was present in 10 out of the 19 sampling stations in Majorca and Minorca
(Fig. 2), indicating that this species is
well established at different locations
around the coasts of both islands. It will
be important to evaluate the temporal
distribution of this species.
The first report of G. australes was in
the Australes archipelago (French Polynesia). This species is also widely distributed in areas such as New Zealand
and the Canary Islands, but it had not
been reported yet in the Mediterranean
Sea. Some studies mentioned that the
spatial expansion of Gambierdiscus and
CFP may be related to the increase of
temperatures caused by climate change
Fig. 1. Epitheca (a) and hypotheca (b) of Gambierdiscus australes cells stained with Calcofluor White.
22
HARMFUL ALGAE NEWS NO. 59 / 2018
Harmful Algae News An IOC Newsletter on Toxic Algae and Algal Blooms No. 59 - February 2018 www.ioc-unesco.org/hab Content 25 years of HAN and IPHAB...... 1 25 YEARS Harmful Algae News was first published in early 1992 in response to requests from the participants at a number of IOC meetings and
pacted by harmful algal events. Since Harmful Algae News turned 20 years old in 2012, it has been a web based e-newsletter which meant longer issues were possible and back issues easily accessible. We are currently working on a searchable index for all Harmful Algae News issues. The start of Harmful
Intergovernmental Panel on Harmful Algal Blooms also turned 25! During 1992, the same Year as the IOC published the first issue of Harmful Algal News, it also established an Intergovernmental Panel on Harmful Algal Blooms (IPHAB) which has met every second year since it was formed. The Panel is com
A retrospective look at the early days of HAB cyst research, and a look to the future On this occasion of the 25th anniversary of the publication of Harmful Algae News, several of us were asked to look backwards in time to some of the earlier days of HAB science. One area of study that has been a ma
dormant stages and that these stages might be associated with certain bottom sediments. This then brings up the question, if benthic resting stages of certain dinoflagellates actually seed coastal red tides, are there localized areas of accumulation, or what we could call seedbeds?..........The poss
day, we still do not know if there are other factors at work perhaps a density-dependent or quorum-sensing type of response, or even a response to the presence of grazers or parasites. Exploration of this response has long been limited by the constraints associated with laboratory cultures, but now
approach did not stand up to data at my study locations. I raise this issue in this narrative because I want to correct what I feel are unjustified recommendations that may prevent those working on cysts from obtaining the type of biological data that can advance our understanding of certain types o
number of cysts in subsurface layers unable to germinate or emerge, presumably due to lack of oxygen or to the tortuous pathway posed by sediment grains and detritus. Many might think that major storms and waves can erode significant layers of sediment and transport cysts long distances, but here ag
How do algal blooms kill finfish and how can we mitigate their impacts? Algal blooms, water discolorations and their association with fish kills have been recorded since historic times, such as the description in the Bible (1000 years BC) all the waters that were in the river were turned to blood. A
Table. 1. Economic losses from algal blooms for finfish aquaculture in different parts of the world HAB species Chattonella Heterosigma Cochlodinium polykrikoides Heterosigma Chaetoceros Heterosigma Karenia digitata Karenia mikimotoi Country Financial Losses Japan Korea, China Canada British Col
emergency harvest operations. To prevent the buildup of histamines, fish should be kept alive as long as possible during harvesting. This can be achieved by diluting algal concentrations via airlift upwelling, or by targeted in-pen emergency application of clays [23] that mop up ichthyotoxins at cla
As part of the 25th anniversary issue of Harmful Algal News I am providing an overview of the IOC-UNESCO Taxonomic Reference List of Harmful Algae (www. marinespecies.org/hab/) and will highlight some of the problems which have faced or are facing the Intergovernmental Panel on Harmful Algal Blooms
Dinophyceae the authors intended the new genus to be described according to the botanical nomenclature. The lack of a Latin diagnosis therefore made it invalid. The confusion has actually still not been resolved, and the problem needs to be discussed and decided upon by the International Nomenclatur
geographically widespread species being able to form fertile offspring, while other populations of the same species are not. Molecular techniques have contributed very significantly to solving many taxonomic problems, but they have not resulted in the emergence of a finite species concept. We have t
Algal toxin discovery, management and regulation over the last 25 years Algal toxins in the dark ages (pre-1992) From a historic perspective, knowledge about algal toxins can be divided into truly prehistoric occurrences such as known from paleontological studies [1-2] and more recent historic recor
lar rapid increase in known analogues has been observed for the azaspiracid (AZA) group, with the first analogue described in 1998 [64] and a review in 2014 reporting 30 analogues [65]. Only three years later, over 50 analogues are known for this group, including novel phosphate derivatives [66-71].
Butterflies in Brazil Abstracts are not always reliable guides to authors intentions. They are not expected to reveal a great deal about the evidence to be deployed in support of the science, evidence that may not even exist before deadlines for writing abstracts! Nevertheless, as examples of a mino
on a decadal time scale, and identified palaeoclimatic oscillations are not necessarily a useful guide to its interpretation. An obvious obstacle to detecting climate signals in HAB data is posed by anthropogenic eutrophication. Another obstacle is the fact that phytoplankton respond directly to the
trends, Karenia brevis might appear more often in the South Atlantic Bight of the US and Gymnodinium catenatum bloom more often in northwestern Iberian waters. There was also a warning by Barrie Dale germane to such speculations, that large scale climate models cannot predict local changes. Little m
Red tides in Kamchatka coastal waters (Bering Sea, Russia) are a barrier for the salmon fishery and Pacific salmon Fig. 1. Map of Olyutorskiy Bay (Kamchatka, Bering Sea) where a red tide, reported by fishermen, occurred in July 2017. The stars denote fishery sites: red, affected by the bloom; green
Fig. 2. Red tide in Olyutorskiy Bay on 15th July 2017 grounds of the Olyutorskiy Bay river basin performed during the second half of August showed an atypical distribution in the rivers. Maximal escapes were recorded in river basins located in the western and eastern parts of the Olyutorskiy Bay ar
First report of Gambierdiscus in the Western Mediterranean Sea (Balearic Islands) Gambierdiscus (Dinophyceae) species are benthic dinoflagellates living in marine littoral zones of circumtropical areas and have recently been described in temperate waters [1]. Some species are producers of potent neu
the SEASENSING (BIO2014-56024C2-2-R) project and the CERCA Programme/Generalitat de Catalunya. A. Tudó and A. Toldrà acknowledge IRTAURV-Banco Santander for their respective PhD grants (2016 PMF-PIPF-74 and 2015PMF-PIPF-67). The authors are grateful to Vanessa Castan and José Luis Costa for sampling
Comparison by light microscopy and qPCR of potentially ichthyotoxic microalgae in Danish on-shore lagoons producing European flounder (Platichthys flesus): Pros and cons of microscopical and molecular methods Fig. 1. Lagoon used for production of European flounder at Fishlab, Denmark. Evaluation o
Fig. 2. Comparison of phytoplankton species identification and cell densities (cells L-1) by qPCR (A and C) and light microscopy (target species and groups which potentially could comprise ichthyotoxic organisms) (B and D) in lagoon 1 (A and B) and lagoon 6 (C and D), respectively. The right Y-axis
present in a sample then qPCR would miss those probably due to lack of a developed assay. However, LM does require high levels of taxonomic skills and the precision in identification is only as accurate as the taxonomist allows. Different taxonomists trained in different ways using different identif
As qPCR measures genetic material rather than viable cells an over estimation of cell numbers can occur due to the inclusion of dead or dying cells. Problems may also occur when targeting multiple copy genes where the organism carries different numbers of the target depending on nutritional status,
The Cawthron Institute Culture Collection of Micro-algae (CICCM) The CICCM is designated as a nationally significant database by the New Zealand government and so receives partial funding for its continued existence. Isolates from 13 classes of micro-algae are maintained either as live cultures or c
The XVIII International Conference on Harmful Algae is approaching! It is time for nominations for achievement awards (Yasumoto Life Time and Patrick Gentien Young Scientist), registration to the conference as a student if you wish to participate in the Maureen Keller Award competition and fundraisi
Forthcoming Events First announcement of the 11th International Conference on Toxic Cyanobacteria (ICTC) We are pleased to disseminate the first announcement of the 11th International Conference on Toxic Cyanobacteria (ICTC) that will be held in Krakow, Poland from May 5 10, 2019. The ICTC is a per
International Coordination of Research on Harmful Algal Blooms From GEOHAB to GlobalHAB International cooperation is fundamental to advance understanding of HAB dynamics and to improve our ability to predict them. Fostering this international cooperation was the mission of GEOHAB (Global Ecology and
18th International Conference on Harmful Algae www.icha2018.com IMPORTANT DEADLINES Abstract submission deadline: 15 April 2018 Early bird registration: 15 July 2018 Get the 17 ICHA Proceedings at www.issha.org Eds-in-chief Beatriz Reguera, IEO, Vigo, Spain Eilen Bresnan, MARLAB, Scotland, UK Regi